Trump is a total clown, My reading of the streams and from what those dastardly clever analysts have worked out, and a bit of my own reasoning is :
Because there was no planning, no expectation, that this was a spur of the moment last second whim thing where the clown said "go":
There is nobody for Iran to surrender to. No forces ready to step in to secure anything. And Iran is a bloody big place.
Ammo is low. Especially the Gulf States. The analysts have compared their military spending against cost and what they have fired and US industrial capacity/ output... and they can only defend against drones/missiles for a few more days. After that, practically defenseless. And it's important to note that the gulf states are defending the US bases. Trump had already used 40% of Thadd missiles in last years attack. Isreal has been sucking up all the Patriots the US can make. And Ukraine have been getting all the older missile systems which have to be replaced with new.
Trump has likely said his "4 weeks " thing, because the Generals told him at the start there is only 4 weeks of ammo stockpiled - for US forces. If they resupply allies, that 4 weeks drops dramatically. At calculated rate of use.
He has no budget from congress to pay for replenishment,
Iran has been preparing for this single thing for 50 years. If Trump does not get their stocks of missiles soon Iran can keep firing. I reckon Iran will have well hidden factories. In the mountains etc.
I am certain he is desperate for Diego Garcia so he can carpet bomb with B52 loaded with "dumb bombs". They have plenty of them compared to the smart and high tech stuff.
Other nations are watching and counting the Ammo too. TW are nervous. They have limited ammo. The plan was for them to defend for a few days till reinforcements arrive.
The US are using AI to identify targets. And that is terrifying. Using intel from a country closed for decades, is that a missile factory or a school ?
Iran has warned it's people. Any sign of trouble and it's an iron fist.
Not as good as AI sorry, but that's my take.